1. Field of the Invention
The present invention relates to digital data storage, and more particularly relates to digital data storage in video format.
2. Background Art
The advent of the laser optical disc has given rise to the hope that this new storage medium might provide a breakthrough for low cost, high density digital data storage. Laser optical discs have already been marketed in connection with home video playback systems at prices within the range of many consumers. It has been proposed that the laser optical disc could be used for the storage of digital data for interface with a computer.
Comparing the storage capacity, in millions of characters, of the laser optical disc with that of a hard magnetic disc, the hard magnetic disc has a storage capacity of only 313 million characters, as compared with 12,500,000 million characters for a laser optical disc. By further comparison, the floppy disc, which is frequently used in connection with home and small business computers, has a storage capacity of only 2.5 million characters.* If it were possible to utilize effectively for computer data storage, the very large storage capacity of the laser optical disc, would result in a tremendous advantage because of the relatively low cost of the optical disc. FNT *Data: RCA Corp., Advanced Technology Laboratories, as reported in Business Week, July 7, 1980, at page 80.
The idea of storing digital data in a video format, that is, storing the digital data as video level signals between the sync pulses of standard NTSC, PAL, or SECAM video signals, so as to permit the use of video processing equipment already developed for storage media such as the laser optical disc, has been proposed. However, there presently exists the need for a practical and reliable method and apparatus to bring into reality such a video format digital data storage system for use with video signal storage media such as the laser optical disc.
The present invention satisfies this need.